Transport Initiatives LLP is an independent transport planning consultancy. They have carried out an audit for Three Rivers District Council classifying roads, paths and crossings in terms of the UK National Cycle Training Standard (Bikeability) Level needed to be able to ride in comparative safety. The results can be seen on Three Rivers District Council's web site.

Transport Initiatives have classified the roundabout at M25 Junction 17, the adjacent Maple Cross Roundabout, and the dual carriageway between them as Level 3.5, i.e. "Roads & crossings with a very high level of risk, unsuitable for even highly experienced cyclists".

For detailed documentation, please see

http://www.threerivers.gov.uk/Default.aspx/Web/CyclingInformation

and download

Maps by area|Maple Cross

plus

Cycling safety audit|CSNA Leaflet